The present invention relates to the quantitative analysis of a plurality of anions or cations in a single system.
The principle of ion exclusion chromatography with resins is known to be useful in separating strong acids or their salts as a class from weak acids or their salts. The theory of separation is that the resin network constitutes a semipermeable membrane from which highly ionized molecules such as mineral acids are excluded and pass through the column in the resin void volumn peak. While less ionized anions may be resolved by this technique and separated from the strong anions, the latter ions are not resolved from each other. The weak anions may be passed to a conductivity cell for quantitative detection providing water or other polar compounds are used as eluent.
Highly ionized ionic species have been resolved by ion exchange resin techniques and quantitatively detected as by use of a conductivity cell. A system of this type is set out in Small et al U.S. Pat. No. 3,920,397. However, the use of this technique is not capable of fully resolving a single sample containing strong and weak ionic species.
There is a need for the rapid analysis of the total ionic content of a sample stream which is rapid and accurate even at low concentrations.